This word uses the kun'yomi reading of the kanji, but you haven't learned it yet. Here's a mnemonic to help you:
Dew is just the earth's way of giving water to you (つゆ). Rain is too forceful, you may not go to the ocean or a lake, so the earth gives dew to you by putting it on the grass outside your house everyday!
I’m collecting dew that’s on the leaves.